Means for varying the effective force on explosively actuated fasteners



Patented May 11, 1954 2,677,823 MEANS FOR VARYING THE EFFECTIVE FORCE FASTENERS ON EXPLOS IVELY ACTUATED Roy M. Magnuson, San Jose, Calif., assignor to Powder-Power Tool Corporation, Portland,

Oreg., a

corporation of Oregon Application September 16, 1953, Serial No. 380,567

2 Claims.

The present invention relates to tools of the type employed for an explosive action in various faces including concrete walls stud driving installing studs by types of wall surand steel struc- The present practice in the use of such stud driving tools is to provide a plurality of cartridges with different amounts of explosive charge, which are selectively employed in accordance with the character of the stud and the character of the wall surface in which the stud is to be driven. 'I'his requires not only an inventory of the various sizes of cartridges on the part of the supplier, but also a similar inventory of such cartridges by the user, and the transporting of the various types of cartridges to each particular job, so that the operator will be sure to have the proper charge for use as different conditions are encountered in installing the studs on the job. Quite often, a job is delayed because of unforeseen requirements for a cartridge with a particular explosive charge.

In accordance with the instant invention, a standard cartridge is employed having a standard explosive charge, but the eifective power or force applied by the cartridge upon explosion thereof is controlled or varied to meet the particular requirements of made.

The above and other objects of the invention are attained in connection with a preferred embodiment of a stud driving tool, as disclosed in the accompanying drawings, and as brought out in the description made in conjunction with said drawings, in which:

Figure 1 is an elevational view of a stud driv- .ing tool with certain parts broken away and shown in section to illustrate the ring or combustion portion of the tool.

Figure 2 is an enlarged fragmentary sectional view similar to a portion of Figure l.

Figure 3 is a fragmentary sectional view taken along planes indicated by the line 3 3 in Figure 2.

This application is a continuation in part of my copending application Serial No. 135,114, filed December 27, 1949.

Referring to Figure 1 there is shown a stud the installation to be driving tool of the character described and claimed in the copending applications of Smith and Daugherty, Serial No. 124,078, led October 28, 1949, for Stud Driving Tool, and Erickson and Bullwinkle, Serial No. 130,818 filed December 2, Driving Tool. In general, stud driving tools of this character be separated or broken in two a rear half IG which contains the various firing control parts including, for example, a ring pin carrier I I, and a front or barrel half I2 of the two halves of the tool. The barrel |311 is also provided with an enlarged bore in which a combustion chamber insert I4 is provided in which the stud I6 to be driven is mounted and to also stud is to be driven and pressing or telescoping the barrel assembly I2 and the firing pin carrier II back into the other portions of the tool until a firing position is reached, as disclosed in said applications, and

of the stud. In accordance with effective force of the the combustion chamber to atmosphere or to an additional or auxiliary combustion chamber providing an additional volume for expansion of the gases. Referring to Figure 3, there is shown a barrel |3b having a second threaded portion 3l thereon spaced from the threaded connection to the firing pin carrier Il by a smooth cylindrical surface 32. A power control ring 33, threaded at one end to engage the threads 3| and having an annular surface 34 slidably engaging the surface 32 of the other, is associated with an aperture 36 leading from the surface 34 into the combustion chamber 2l. If desired, the power control ring 33 may be provided with an aperture in its wall leading to the atmosphere. Alternatively the looseness of fit of the thread 3i with the threaded end of the ring 33 may be employed as an aperture for escape of combustion gases. With reference to Figure 2, it will be seen that by selective adjustment of the ring 33 axially along the barrel |3b the passage 36 may be completely covered, as shown in Figure 2, or it may be selectively uncovered in a desired amount to provide a restricted opening between the combustion chamber 2| and the volume within the ring 33 providing an auxiliary combustion chamber or bleed-oil chamber.

From the above description, it will be seen that a selected stud is disposed or placed in operative relation to a combustion chamber with which a standard explosive charge is also associated, and the effective force of this standard charge with respect to the stud is varied in order to apply the desired driving force to the stud. This enables the supplier and the user to maintain a single inventory of cartridges, and always insures that the workman can select, without delay, the right explosive force for a particular stud installation.

While I have shown and described certain preferred apparatus for carrying out the invention it is to be understood that the invention can be carried out by other apparatus so that its scope should be limited only by the scope of the claims appended hereto.

Iclaim:

1. In a device for explosively driving studs into surfaces including a barrel through which the stud is expelled, means at the breech end of said barrel for mounting an explosive cartridge, means for mounting a stud in spaced relation `from said cartridge to provide a combustion space Within said barrel, passage means leading from said space through said barrel to the outer surface thereof, and a ring mounted for axial adjustment on said barrel for selectively opening and closing said passage means.

2. In a device for explosively driving studs into surfaces including a barrel through which the stud is expelled, means at the breech end of said barrel for mounting an explosive cartridge, the means for mounting a stud in spaced relation .from said cartridge to provide a combustion space within said barrel, passage means leading from said combustion space through said barrel to the outer surface thereof, and a ring mounted for axial adjustment on said barrel for selectively opening and closing said passage means, said ring having an internal recess and also having passage means leading from said recess to the exterior surface thereof.

No references cited. 

